/*
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 *  This program is free software; you can redistribute it and/or modify
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 *  Additional permission under GNU GPL version 3 section 7:
 *
 *  KNIME interoperates with ECLIPSE solely via ECLIPSE's plug-in APIs.
 *  Hence, KNIME and ECLIPSE are both independent programs and are not
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 *  you the additional permission to use and propagate KNIME together with
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 *
 *  Additional permission relating to nodes for KNIME that extend the Node
 *  Extension (and in particular that are based on subclasses of NodeModel,
 *  NodeDialog, and NodeView) and that only interoperate with KNIME through
 *  standard APIs ("Nodes"):
 *  Nodes are deemed to be separate and independent programs and to not be
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 *  may freely choose the license terms applicable to such Node, including
 *  when such Node is propagated with or for interoperation with KNIME.
 * ------------------------------------------------------------------------
 *
 * History
 *   12.07.2010 (hofer): created
 */
package org.knime.base.node.preproc.autobinner.apply;

import org.knime.base.node.preproc.autobinner.pmml.DisretizeConfiguration;
import org.knime.base.node.preproc.autobinner.pmml.PMMLPreprocDiscretize;
import org.knime.core.data.DataTableSpec;
import org.knime.core.data.container.ColumnRearranger;
import org.knime.core.node.BufferedDataTable;
import org.knime.core.node.CanceledExecutionException;
import org.knime.core.node.ExecutionContext;
import org.knime.core.node.InvalidSettingsException;

/**
 * Use this in other nodes for binning data.
 *
 * @author Heiko Hofer
 */
public final class AutoBinnerApply {
    /**
     * @param op {@link PMMLPreprocDiscretize} operation
     * @param dataSpec table with data to discretize
     * @return  The spec of the output.
     * @throws InvalidSettingsException If settings are inconsistent
     */
    public DataTableSpec getOutputSpec(final PMMLPreprocDiscretize op,
            final DataTableSpec dataSpec) throws InvalidSettingsException {
        ColumnRearranger rearranger = getRearranger(op, dataSpec);
        return rearranger.createSpec();
    }

    /**
     * Performs binning.
     *
     * @param op {@link PMMLPreprocDiscretize} operation
     * @param inTable the input data table
     * @param exec the execution context
     * @return data table with binned data
     * @throws InvalidSettingsException when settings are inconsistent
     * @throws CanceledExecutionException when execution is canceled
     */
    public BufferedDataTable execute(final PMMLPreprocDiscretize op,
            final BufferedDataTable inTable, final ExecutionContext exec)
    throws InvalidSettingsException, CanceledExecutionException {
        ColumnRearranger rearranger = getRearranger(op,
                inTable.getDataTableSpec());
        return exec.createColumnRearrangeTable(inTable, rearranger, exec);
    }

   /** Create {@link ColumnRearranger}.
    * @param op {@link PMMLPreprocDiscretize} operation
    * @param inTable the input data table
    * @throws InvalidSettingsException when settings are inconsistent
    */
    ColumnRearranger getRearranger(final PMMLPreprocDiscretize op,
            final DataTableSpec dataSpec) throws InvalidSettingsException {
        DisretizeConfiguration config = op.getConfiguration();
        // Check if columns to discretize exist
        for (String name : config.getNames()) {
            String toBin = config.getDiscretize(name).getField();
            if (!dataSpec.containsName(toBin)) {
                throw new InvalidSettingsException("Column "
                        + "\"" + toBin + "\""
                        + "is missing in the input table.");
            }
        }
        ColumnRearranger rearranger = new ColumnRearranger(dataSpec);
        for (String name : config.getNames()) {
            int colIdx = dataSpec.findColumnIndex(
                    config.getDiscretize(name).getField());
            assert colIdx >= 0;
            if (dataSpec.containsName(name)) {
                rearranger.replace(
                        new BinningCellFactory(name, colIdx,
                                config.getDiscretize(name)), name);
            } else {
                rearranger.append(
                        new BinningCellFactory(name, colIdx,
                                config.getDiscretize(name)));
            }
        }

        return rearranger;
    }

}
